1. Field of the Invention
The present invention relates to method and apparatus for changing a drum surface in a printing apparatus and more particularly to a method and apparatus for installing a flexible belt onto a relatively rigid drum in a printing apparatus such as an electrostatic printer.
2. Discussion of the Related Art
A typical document copier includes an electrostatic printer having a belt having a photoconductive surface. To transfer an image onto a sheet of paper, the printer charges the belt to a uniform potential, and then selectively exposes the belt to a pattern of light corresponding to the image. The light discharges parts of the belt resulting in a pattern of charge corresponding to the image, an electrostatic latent image, being formed on the belt. The portion of the belt having the electrostatic image then passes a development station that deposits toner on the belt in the pattern of the image, resulting in a developed image. A sheet of paper is then tacked onto the belt and removed from the belt, resulting in the image being formed on the paper.
A typical electrostatic printer includes rolls that drive the belt and that give the belt shape and support. These rolls are subject to motion in the direction of the rotation axis, or `runout`, and other variations that affect the otherwise uniform motion of the belt. Variations in uniform motion of the belt can adversely affect image quality. Thus, the belt requires tracking to suppress perpendicular motion of the belt relative to the upstream-to-downstream motion of the belt.
Problems caused by these variations in belt motion are exacerbated in single pass full color printers, which require especially accurate placement on the belt of overlying multiple images corresponding to each color component.